Depression is a common mental health problem in adolescence. In this study it was aimed to investigate attachment properties, emotion regulation skills and anger expression patterns in adolescents diagnosed with major depressive disorder (MDD) and to compare the results with healthy controls' findings. Effects of having comorbid anxiety disorder (AD) to these psychological properties were also evaluated. The study was planned as three-centered, single-disciplinary, a cross-sectional study with a control group in Turkey. Depression group was consisted of 97 adolescents while control group was 101 adolescents. All participants were administered Beck Depression Inventory (BDI), Inventory of Parent and Peer Attachment (IPPA), Difficulties in Emotion Regulation Scale (DERS), and State-Trait Anger Expression Inventory (STAXI). Depression group had statistically lower scores in peer attachment and parent attachment, and higher scores in all subscales of DERS compared to the controls. Due to STAXI, it was observed that depression group obtained statistically significant higher scores in trait anger, repression of anger, expression of anger and statistically lower scores in control of anger, compared the controls. There was no difference in state anger between groups. In depression group, there were no significant differences for any promising psychiatric properties between adolescents with MDD and those with MDD + AD. The findings of this study supported that anger expression and emotional regulation difficulties were related with depression and that this relationship was also associated by attachment security. These findings are important for clinical practice to increase understanding of the association between attachment security, emotion regulation, anger expression and depression.